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0. G. BURKE. I 'TELEGRAPHIG INSTRUMENT. No. 405,989. Patented June 25,1889..

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O. G. BURKE. TELBGRAPHIO INSTRUMENT.

No. 405,989. Patented June 25, 1889.

N) L T/nausea am'uamtoz UNITED STATES PATENT ()EEIcE.

CHARLES G. BURKE, OF RICHMOND HILL, ASSIGNOR TO FREDERICK OLFFE,TRUSTEE, OF NENV YORK, N. Y.

TELEGRAPHIC INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 405,989, dated June 25,1889. 7 Application filed March 28, 1889. Serial No. 305,052. (Nomodel.)

To all whom it may concern-.-

Be it known that 1, CHARLES G. BURKE, a citizen of the United States,residing at Richmond Hill, in the county of Queens and State of NewYork, have invented certain new and useful Improvements in TelegraphicInstruments, of which the following is a specification.

The object of the invention is to provide a sensitive receivingtelegraphic instrument suitable for cables and other lines where feeblecurrents are used.

The invention consists, generally, in a cylindrical coil of wire, whichforms part of the main circuit, suspended perpendicularly within a fieldof force formed by one or more magnets, motion of the coil being causedby the currents passing over the main line, of which it forms a part. Animportant feature of this construction is that the suspended coilthroughout the entire range of its motion will preserve the samerelation to the faces of the poles of the fieldmagnets. Anotherimportant feature of the invention consists in the device for making andbreaking a local circuit by means of the motion of the coil.

The invention will be readily understood by inspection of theaccompanying drawings, in which Figure 1 is a side view, partly insection, of the coil and its attachments suspended upon a suitableframe, and showing the main and local circuits in diagram. Figs. 2 and 3are top views of parts of the instrument, and Fig. 4 is also a top Viewof the coil with two magnets having their poles shaped to the coil.

Referring to the figures, the coil A is delicately suspended upon theaxis at, having its bearings within the jeweled holes a. The coil issuspended by the fine thread B, passing through the guide I), andattached to the adjusting-screw b. The coil and its attachments aresupported upon the base 0, having the metallic standard D. The main lineL includes the coil A, being connected thereto by its outer and innerterminals. The coil A being suspended within the field of force of themagnet M, on the passage of an electric current over the main line adisturbance is set up in the magnetic field which causes a tendency tomove inthe coil, one section of the coil being attracted and anothersection repelled. This mutual and simultaneous attraction and repulsionis exercised at a greater or less degree of angularity, and consequentlywith a greater or less intensity, and the coil is so pivoted that anymovement communicated must be around its center, the direction of themotion depending upon the direction of the current and its relation tothe magnetic field.

Upon the axis a of the coil is rigidly fixed an arm E, carrying thecontact-point c at its extremity. One terminal of the local circuit L isconnected with the arm E. The other terminal of the local circuit, whichincludes the sounder D and battery 0, is connected with the frame D, andthrough this with the forked arm H. This arm carries at its extremitythe set-screws h and it, one of them being insulated and the other inconnection with the local battery.

Attached to the arm J of the standard D is the sleeve K, through whichthe cord B passes which supports the coil A. The arm H passes over thissleeve and is free to move thereon. The spring S and adj ustingnuts smaintain a suitable friction between the arm Hand the sleeve K. Thecontact-point 6 plays between the two adjusting-stops h and h, which areaffixed at the free extremities or prongs of the forked arm II.Preferably the play of the contact-point e between these steps is madeas close as practicable, andthe extent of the play may be regulated byscrewing one or both of these steps closer to or farther from oneanother. As the coil A is turned upon its axis by means of the currentspassing over the main line, the rotation of the axis a will communicatemotion to the arm H, which is rigid on it, and the contact-point 6 willbe made to impinge on the stop h or h, as the direction may be. If theelectrical impulse through the coil be prolonged and the potentialincreases beyond the power of resistance exercised by the friction offorked arm A on the sleeve K, then the pressure of contact 6 against thestop to which it has been carried will overcome the friction, and theforked arm and its stops will be moved in the direction to which contact0 tends, and will continue to move so long as the pressure of contact 6against the stop is in excess of the resistance of the friction; and asboth contact 0 and its step are describing the same circle the contactbetween the point e and its step will not be interrupted or brokenduring the whole movement. XVhen the potential on the line falls belowthe power of the frictional resistance of the forked arm N on its sleeveK, further motion will be arrested, and if the coil be then moved everso little in a contrary direction. contact 6 will immediately beseparated from the stop against which it was resting. The forked arm andits stops having no tendencyof their own to move in either direction andbeing moved in the same circle with the arm by which they are moved,contact e and its stops 7L and 7t will necessarily preserve the samerelation to each other throughout the entire range of motion, and thelocal circuit will therefore be made or broken at any point within thisrange of motion so soon as the variations in line-potential will besuili cient to cause motion in the coil in a direction to effect a makeor break. The localeireuit device herein shown is applicable, as willreadily be seen, to any form of suspended coil.

In Fi at is shown the arrangement of two magnets to produce the field offorce, the pole-pieces being curved to correspond with the cylindricalcoil A. By this means the field is intensified by the greater proximityof the poles of the magnet to the surface of the coil, and is an.advantage especially pertaining to this shape.

I claim as my invention 1. In atelegraphic instrument, a cylindricalcoil of insulated wire forming part of the main circuit and suspendedwithin. a field of force formed by one or more magnets, both poles ofthe same magnet being presented to the same side of the coil.

2. In a telegraphic instrument, a cylindrical coil of insulated wireforming part of the main circuit, suspended upon an axis coincident withthe axis of the cylinder within a field of force created by one or moremagnets, both poles of each magnet being presented to the same side ofthe coil.

In a telegraphic instrument, a coil of in s'ulated wire forming part ofthe main circuit,

suspended within a hold of force formed by one or more magnets, and alocal-c1rcuitclosing device consisting of an arm attached to the axis ofthe coil moving with said coil be tween stops carried by a second armturning upon an axis coincident with the axis of the coil.

i. A telegraphic instrun'ient consisting oi. the combination of a coilof wire forming part of the main circuit, suspended within a field offorce formed by one or more magnets, an arm attached to said coil,asecond arm turnin upon. a center coincident with the axis of motion ofsaid coil, carrying stops between which said first arm. plays, and africtional support for said second arm, whereby it may follow themovements of said first arm, both of said arms forming part of thelocal. circuit.

5. In a telegra mic receivinginstrument, a circuit-closing deviceconsisting of two inde pendent movable parts insulated from each other,both forming parts of a common local circuit, one having an. imlependentmotion upon its axis and the other a free motion around the axis of theother, both being equal radii of a given circle, the part turning on itsaxis having a suitable contact-point playing freely between an.insulated stop and a contact-point carried. by and forming a portion ofthe other part, said insulated stop and contact-point being adjustable,the mm'ement of the part turning on. its axis being effected byelectrical impulses over the main. line, the motion of the other beingwholly dependent upon the pressure exercised against its stops bythepart moved by said main line currents, the local. circuit being made atany point within the entire range of motion. of said parts whenever thetwo contactpoints are brought together by the movement of the partturning on its axis, and broken whenever the same are separated by acontrary motion of said part.

In testimony whereof I have hereunto subscribed my name this 27th day ofll'larch, A. D. 1889,

CHARLES G. BURKE.

W'itnesses:

DANL. W. Eoonoon'i-z, CAROLINE E. DAVIDSON.

